Temperature control for oil



June, 1930. w, R STRlCKLAND 1,761,942

TEMPERATURE CONTROL FOR OIL gjvwemtoz `)une 3, 1930. w. R. STRICKLAND n 13,761,942

TEMPERATURE CONTROL FOR OIL Filed May 7, 1928 2 Sher-:ts-Sheetl 2 gwuentoz -Patemd June 3,' 1930 I UNITED STATES-e PATENT orifice WILLIAM R. srRIcxLAND, or DETRoI'I", MICHIGAN, AssIGNoR To GENERAL MoroRs coRIoRATIoN, or DErRoIr, MIcHIeAN, A CORPORATIONI ORDRLAWARE TEMPERATURE CONTROL FoR oILl Application tiled May 7, 1928. Serial No. 275,739.

It has proven difiicult to maintain the oil in modern high speed, high conipression in'- ternal combustion engines at suiiiciently low temperatures to insure retention of its lubricating properties.. Under some conditions it has been found that the oil reaches a temper-vv ature as high as 250 F. At/these tempera- Itures its efficiency as a lubricating agent is low due to its greatly reduced viscosity. `More or less permanent deterioration of the oil also results `from the excessive heat. It has been found by tests to bevery desirable to maintain the oil supply'v at temperatures not exceeding 170 F.

I propose tomaintain the oil at the desired lower temperature by providing a cooling system including a heat absorbing element or vcooler located in the crankcase or other oil receptacle and circulating through the cooler a suitable iiuid in such manner that the iiuidabsorbs the heat fromthe oil, is vapor\ ized and subsequently condenses and returns to the cooler. By this arrangement I make use of the latent heat of the fluid as a factor in cooling and am. enabled to lconduct away a'large amount of heat with cooler o f small size and with the employment of a relatively small quant-ity of cooling liquid. The inventive idea is susceptible of great variation in itspractical embodiment. In the simplest form the cooler is arranged-in a ley-pass in the engine cooling system and receives water therefromunder a slight head or'ldegree of pressure, this pressure however being insuffi-y cient to cause active fiow of Water through the cooler prior to boiling. y As a modification of my system I may provide'a separate radiator or condenser for the vapor generated in my cooler instead of employing the engine cooling radiator for the purpose. In such event I may make use of some fluid other than Water as the c oling medium.y Such fluidsas alcohol, having boiling temperatures around 170', have advantagesfor this. purpose-because the latent heat 'becomes an effective factor in cooling long before the oill has reached'undesirably high temperature. vFluids with evenlower boiling points would have'- greater advantages in this respect.

l Instead ,of locating the cooling coil in 'the crankcase I may arrange to pump the crankcase oil throughy a lubricant Areservoirl equipped with a suitable cooler. This varia-- tion may be made in either ofthe forms of the invention previously described.

All of the forms of'my invention possess the advantage that the-coolingis accomplished by means of a cooling system of maxi-` mum effectiveness and of minimum size, this advantage resulting from the employment of the latent heat of the fluid.

In the drawing: Figure 1 is a diagrammatic `view showing the application of one form-of my invention to an internal combustion engmine. In Figure 2 I have shown a modified form in which -thefoil cooler is connected to a sepa rate radiator.

In Figure 3 I have shown a further modification in which the oil' from the engine is forced through a/cooling chamber separate from the engine crankcase, thisv chamber'containinga. cooler in the form of a radiator through whichiluid is circulated. The cool.-

ing liquid may be condensed in either of the ways shown in Figures 1 and2.

In Figure 1, 1Q indicates an internal com- I,

-bustion engine provided with the usual radiator'12 for the engine cooling system. This radiator maybe of the conventional type provided With top-and bottom tanks connected by a honey comb or finned tube core. It is illustrated as of the vertical. flow type but a cross flow radiator maybe used ifpreferred. The pump 14 'draWsv'ater from the bottom tankof thej radiator and s'upplies'it to the water jacket ofthe engine through any suitable conduit shown at 16. The Water which has performed its function of cooling the enlgine* is vconducted to the top tank of the radiator through conduit 18.. Thespecific cooling system illustrated is conventionaland may be varied as'desired. 2O indicates the crankcase of the engine within which is located an oil cooler 22' in the form of ,sp'acedlieaderslf and 26 connected by parallel tubes 28. This, cooler is likewise conventional and may be modified'as desired. QA pipe'30 leads from a suitable point in the cooling system, such as the lower tank, to the bottom of the header i the condenser, the cooler being so arranged as 24 and a tube 32 leads from the top of this vsame header to a higher point in the cooling system. I have preferred to project the upper end of the tube 32 into the connection 18 with its-open end v34 facing in the direction of water flow so that it is subject to'the suction produced by the circulating cooling water.

With this arrangementit is apparent that the water in the cooler 22 is practically static. It will remain so until it absorbs suflicient heat from the oil to cause it to boil. Steam will then be discharged through the outlet 34 and will be condensed either by contact with the following stream or in the radiator 12.

Obviously the connection of the oil cooler with the engine cooling system may be made at other points than those shown. The pipev 32 may lead to the upper tank of the radiator l2 if preferred.

By thisl arrangement `it is apparent that the latent heat of the fluid in the cooler 22 is utilized to cool the oil so that a less quantity of cooling fluid is required than would be the c'ase Were this phenomenon notrelied upon.

In the modification shown in Figure 2 the prising a fluid containing oil cooler associated with the reservoir, a condenser, connections from the cooler to the condenser, said I VILLIAM R. STRICKLAND.

pipes 30 and 32 connecting with the oil cool- 1 er are connected to' a separate condenser 40. This may be located in any convenient place.

In the modification shown in Figure 3 the oil cooler48 is shown located in an/ oil reservoir 42 supplied with oil from the crankcase 20 by means of pump 44 and conduits 45 and 46. The coolingfluid supplied to the oil cooler 48 may either be provided with its own condenser, as shown in Fig.n2, or they radiator of the engine cooling system may be employed for this purpose as shown in Figure l.

Since the rate of heat exchange between the oil and the cooling fluid depends on the differencel in temperature between them it may be found desirable `in'some instances to use some fluid other than water as the cooling medium. Such fluids should have boiling points lower than water in order that boiling may take place while the temperature difference between the oil and the cooling fluid is greater than in the case of water, thus for some purposes alcohol may prove satisfactory.

I claim: I

l. The combination of an internal combustion engine provided with a lubricating system'including a lubricant reservoir, a cooler in the reservoir containing a cooling fiuid, a.;

condenser, connections between the cooler and to maintain the iuid in static state until circulation is produced by boiling of thel fluid, thereby making use of the latent heat of the fluid as the means of heat transfer.

2.- An oil cooling system for an internal combustion engine provided with cooling means and with a lubricant reservoir, com- 

